The primate pelvis: Allometry or sexual dimorphism?

Abstract

In several primate species the pelvic skeleton exhibits marked sexual dimorphism. Some workers have proposed that the structure of the female primate pelvis is influenced by the presence of the birth canal, but others have sought to explain pelvic dimorphism as the allometric consequence of differences in body size between the sexes. Measurements of five pelvic dimensions together with the length of the femur (an indicator of overall body size) were obtained for several species of primates including modern man. In some species the females exhibit differential pelvic growth, resulting in a difference between the size dimorphism of the pelvis and that of the femur. Differential female pelvic growth is confined to pelvic dimensions that are related to the size of the birth canal, confirming previous suggestions that relative neonatal size is a determinant of pelvic dimorphism in primates.